Screening system

ABSTRACT

A modular screening system which includes a plurality of screening modules supported in an interlocking manner of clamping bars secured to and positioned across a screening machine in parallel spaced relationship. The modules have a peripheral portion defined by side and end walls with a plurality of openings extending through the modules inwardly of the peripheral portion. The side and end walls of the modules are provided with interengaging means which interlock with longitudinal and transverse channels in the clamping bars to secure the modules in position in the machine, the modules are provided with interengaging means whereby the modules interlock together.

The present invention relates to a new and improved modular screeningsystem for use in screening machines.

Modular screening systems are known and were developed to overcome theproblem of localised wear in a continuous screening mat which was usedin such machines.

The present invention provides an improved modular screening system foruse with screening machines.

SUMMARY OF THE INVENTION

In accordance with the present invention there is provided a modularscreening system which includes: a plurality of screening modulessupported on clamping bars secured to and positioned across a screeningmachine in parallel space relationship, said modules having a peripheralportion defined by side and end walls and a plurality of openingextending through said modules inwardly of the peripheral portion, theside and end wall of the modules being provided with inter engagingmeans which interlock with longitudional and transverse channels in saidclamping bars to secure said modules in position in the machine.

According to one embodiment the interengaging means comprisesprotuberances on the side and end walls of each module.

In a modification the interengaging means comprises protuberances on theinside faces of the side walls of the modules and a transverse railinterlocked with the end walls of the modules.

The invention will be now more particularly described with reference tothe preferred embodiments shown in the accompanying drawings.

DESCRIPTION OF THE DRAWINGS

FIG. 1 is an exploded respective view illustrating two modules and twoclamping bars according to one embodiment of the invention;

FIG. 2 is a diagramatic plan view of an assembly of modules;

FIG. 3 is a diagramatic side view in the direction of the arrow III onFIG. 2;

FIG. 4 is a detailed cross sectional view on line IV--IV of the modulesof FIG. 2;

FIG. 5 is a detailed sectional view on line V--V of FIG. 2;

FIG. 6 is a perspective view of the under sides of a module and

FIG. 7 is a perspective view similar to FIG. 1 illustrating anotherembodiment of the invention.

DETAILED DESCRIPTION OF THE INVENTION

Referring now to the drawings. The screening module is designatedgenerally by the reference 1. It is preferably made from polyurethaneand has ends 2 and 3 and sides 4 and 5 defining the peripheral portionof the module. The module is conventiently formed in a moldingoperation, the peripheral portion is provided with reinforcementpreferably in the form of steel strips or bars 6 and 7 and in additionthe module is provided with a plurality of openings formed bylongitudinal members 8 and transverse members 9. These members may beprovided with reinforcement in the form of reinforcing bars embedded inthe longitudinal member 8 and transverse members 9. The size of theopenings will be selected to suit the particular requirements of thematerial to be screened.

As illustrated in FIG. 1 adjoining modules are designed to interlock onewith the other and to be firmly and accurately supported on clampingbars 16 in such a manner which will prevent small pieces of aggregate,dust particles and water from penetrating between mating servicesthereby minimising wear. To this end each end wall 2 is provided with alongitudionally extending protuberance 10 while the opposite end 3 isprovided with a longitudionally extending channel 11 as clearly shown inFIG. 5. The channel 11 is so shaped and dimensioned as to accuratelyaccommodate and mate with the protuberance 10 of an adjoining module asillustrated in FIG. 5.

The end walls 2 and 3 each include an integral skirt portion 12 whichextend below the bottom edge of the side walls 4 and 5 illustrated inFIG. 6. The inner face 13 of this skirt is provided with an arcuateshape protuberance 14 (FIG. 6). Whilst it is possible for theseprotuberances to extend throughout the length of the skirt it ispreferred that they only extend for such a length as to be completelyaccommodated in a transverse channel designated generally by thereference 15 in the clamping bar 16 as illustrated in FIG. 1. The innerfaces of the side walls 4 and 5 are each provided with a protuberance 17which may extend throughout the length of the end walls or only part wayas circumstances dictate.

The clamping bars 16 are also preferably made of polyurethane and extendover the length of the machine, the side wall of which are identified bythe reference numerals 18 and 19 in FIGS. 2 and 3. Each bar seats onsupport members 20, 21 and 22. The support members are preferably madefrom steel and are secured over the length of the machine in parallelspaced relationship. The members 20 and 21 are conventiently formed asright angle shaped bars, whilst the members 22 which are located in thecentre of the machine are channel shaped for greater strength.

Each clamping bar 16 is provided with bores 23 which are spaced alongeach bar so as to register with the support members 20, 21 and 22. Thebore passes through a reinforcing bar 24 embedded in the clamping barduring the manufacture thereof. Bolts 26 seating on washers 27 passthrough holes 28 in the reinforcing bar 24 and are secured by nuts (notshown) to the support members 20 21, and 22.

Each clamping bar is provided with a centrally located longitudionallyextending channel 29 in its upper face and of course the transversechannels 15 previously referred to. The longitudional channel 29 hasstraight side walls 30 and 31 forming lips leading to a circular shapedbottom portion 32. The transverse channels 15 likewise have straightside walls 33 and 34 also forming lips leading into a circular shapedbottom portion 35. As will be apparent from FIG. 1 the longitudionalchannels 29 intersect the transverse channels 15 at right angles.

With the support members secured in the machine and the clamping barssecured to the support members in the manner previously described thescreening modules 1 are locked in position as follows. The module ispositioned on the clamping bars with the end walls 2 and 3 in registerwith the horizontal channels 15 and the side walls 4 and 5 in registerwith the longitudional channels 29. The module is then presseddownwardly so that the sides and end walls of the module enter thehorizontal channels 15 and the longitudional channels 29. Adjoiningmodules are positioned and locked in position in the same manner, therebeing sufficient resiliency in the lips formed by the walls 30, 31 and33, 34 to permit the sides and ends of the module to be tightly lockedin the respective channels.

As will be apparent from FIG. 1 the protuberances 10 of each module snapinto the channel 11 of an adjoining module. The interlocking ofadjoining modules and the locking of the respective modules to theclamping bar in the manner described insures a tight fit and so dust andaggregate particles and moisture cannot penetrate between the interfacesof the components thereby minimising wear and ensuring long life.Additionally no separate fasting means are used and worn or damagedmodules may be removed and replaced in a matter of seconds.

Wear plates 36 are provided to protect the side walls 18 and 19 of themachine. These plates are preferably made from polyurethane and asindicated in FIG. 4 they include a longitudionally extending body havinga downwardly extending tongue 37 having the bottom portion of its sideface formed with a protuberance 38 of the same configuration as thebottom portion 35 of the channel 29. In use the tongue snaps into thelongitudional channel 29 and bears tightly against the adjoining moduleand the wall.

Referring now to the embodiment of the invention illustrated in FIG. 7in which like parts are given the same reference numerals as that of theprevious embodiment.

The module 1 has end walls 2 and 3 and side walls 4 and 5 defining theperipheral portion of the module. As in the case of the previousembodiment the module is formed of polyurethane in a moulding operation.The peripheral portion does not however include the reinforcementdescribed in the previous embodiment. The module is however providedwith a plurality of apertures formed by the transverse members 8 and thelongitudional members 9.

In the case of this embodiment the bottom edge 39 of the end walls 2 and3 is provided with a downwardly opening channel 40 having limbs 41 and42. The inner face of the limb 41 is provided with an inwardly directedprotuberance 43. The protuberance may extend throughout the length ofthe end walls of the module or it may only extend over a portion of thelength as circumstances dictate.

The modules are supported on rails designated generally by the reference45 which in turn are supported on the clamping bars 16. The bar 16 seatson the support members 20, 21 and 22 and is secured thereto by bolts 26.The clamping bars are provided with horizontal channels 15 andlongitudional channels 29 as described in the previous embodiment.

The rails 45 extend transversely across the machine and are adapted toseat in the transverse channels 15. Each rail is substantially U-shapedhaving a bight portion 46 with a reinforcing bar 47 embedded therein andextending throughout the length of the rail. Limbs 48 and 49 extendupwardly from the bight portion and define a channel 50. In order toensure a tight interfit with the transverse channel 15 the outer facesof the side walls of the rail are provided with arcuate shapedprotuberances 51 and the outer face of the bottom portion of the railsare rounded as at 52 to provide a section which is complementary to theshape of the transverse channels 15. As will be apparent from FIG. 7 therails 45 snap into the transverse channels 15 and are tightly engagedthereby with the surface of the rails and the clamping bars beingplanar.

The clamping bars and rails form a grid like structure which extendsacross the machine and supports the modules. The modules are simplypressed into the longitudional channels 29 and the channels 50 in therails 45 with the protuberances 40 engaging the inner face of thechannels 50. Adjoining modules are likewise pressed into theirrespective transverse and longitudional channels thereby forming a rigidtightly interlocked screening structure.

As in the case of the previous embodiment worn or damaged modules may bereplaced within a very short time without the necessity of releasingspecial securing means such as nuts, bolts, screws and the like. Wearplates 36 protect the sides 18 and 19 of the machine in the same manneras described with the reference to the previous embodiment.

What is claimed is:
 1. A modular screening system positioned andlockingly supported across a screening machine,said modular screeningsystem comprising a plurality of screening modules with screen openingtherein, each module being characterized by a rectangular peripherydefining end walls and side walls, said modules being disposed inparallel and contacting relationship with each other, protuberance meansextending along an outer face of one end wall of each module, andchannel means extending along an outer face of the other end wallthereof, such that the end wall protuberance means of one of saidmodules interengages and mates with end wall channel means of anadjacent module, clamping bars disposed in spaced relationship acrosssaid screening machine beneath said modular screening system,each ofsaid spaced clamping bars being disposed transverse to the end walls ofsaid modules, each of said clamping bars having a longitudinal channelrunning along its length with spaced channel locking means disposedtransversely to said bar and the longitudinal channel thereof,detachable rails disposed below said screen modules in spacedrelationship across and transverse to said clamping bars and to the sidewalls of said modules and above said clamping bars, each of said railshaving locking means in the form of protuberance means which snap-fitinto said transverse channel locking means on said clamping bars,each ofsaid rails having channel means longitudinally disposed therein,protuberance means located at the bottom of each module end wall whichsnap-fit into said rail channel means disposed along each of said spacedrails, and protuberance means located at the bottom of the side walls ofeach module which snap-fit into the longitudinal channels of saidclamping bars, whereby adjacent modules are interlocked relative to eachother and to the rails and the clamping bars.
 2. The modular screeningsystem of claim 1, wherein the protuberance means on the inside faces ofeach side and end wall of each module are semicircular and extend atleast part way along the length of each of said walls, each of saidprotuberance means and adjoining wall sections being so dimensioned asto occupy approximately one half the width of the corresponding rail andclamping bar channel means, the other half of the width of the saidchannel means being occupied by the protuberance means and adjoiningwall sections of the side and end walls of an adjoining module, wherebysaid modules are locked in position on said rails and said clampingbars.
 3. The modular screening system as claimed in claim 1, wherein thetransverse channel means of the clamping bars intercept the longitudinalchannel means thereof at right angles, said transverse channel meansbeing deeper than the longitudinal channel means, said transverse andlongitudinal channel means of said clamping bars having a keyhole shapein cross-section.
 4. The modular screening system as claimed in claim 1,wherein the protuberance means on each side wall of said rails extend atleast part way along the length of each side wall, said protuberancemeans on said rail having a shape which is complementary to the shape ofthe transverse channels in said clamping bars and is capable of beingsnap-fitted therein.
 5. The modular screening system as claimed in claim4, wherein the modules are supported on said clamping bars and rails,the rails being provided with interengaging means which interlock withthe transverse channel means in said clamping bars and thus provide agrid structure extending across the machine, the bottom edge of the endwall of each module being provided with a downwardly opening channelmeans, one wall of which has protuberance means extending inwardly intothe channel and which is complementary in shape to the shape of half thecross-sectional shape of the channel in said rail, said protuberancemeans being adapted to enter and seat in one half of said channel, theprotuberance means of an adjoining module being adapted to enter andseat in the other half of the said channel means, whereby adjoiningmodules are locked in the said rail.
 6. The modular screening system asclaimed in claim 4, whereby said rail has a reinforcing bar embeddedtherein.
 7. The modular screening system as claimed in claim 1, whereinsaid clamping bar is secured to support members extending across saidmachine.
 8. The modular screening system as claimed in claim 1, whereinwear plates are provided to protect the sides of the screening machine,said wear plates having a tongue provided with protuberance means whichis complementary in shape to substantially half the cross-sectionalshape of the longitudinal channel means of said clamping bars, saidtongue being adapted to enter into said channel and to be locked thereinwith the side walls of an adjoining module.